New Book: Chapter 1- Sight and Sound

Sound designer Randy Thom (The Incredibles, The Polar Express, Harry Potter and the Goblet of Fire...etc.) states that film sound can:
***-Suggest a mood
-Set a pace
-Clarify the plot
***-Define a character
-Connect otherwise unconnected ideas, characters, places, images, or moments
-Draw attention to or away from a detail
-Indicate changes in time
-Smooth otherwise abrupt changes between shots or scenes
-Startle or soothe

Sound Design: Sound design has three main elements:
                                                                                     -Music
                                                                                     -Noises
                                                                                     -Voices

In olden days, everything on the soundtrack had to be recorded at the same time. Today, everything (the music, noises, and voices) is recorded separately and then put together after the film has been shot. (The person who combines these sounds is called the "sound mixer"). The noises on the soundtrack are called sound effects and can be simple (the squeak of a door hinge) or complicated (a nuclear bomb blowing up). Most action movies depend greatly on sound effects (Star Wars, Die Hard, The Matrix).